Control mechanism



P 1964 J. H. SWATS ETAL 3,149,500

CONTROL MECHANISM Original Filed Oct. 21, 1957 8 Sheets-Sheet 1INVENTORS JOHN H. sWATS Smuv E. HAGERTY ATTORNEY Sept. 22, 1964 J. H.SWATS ETAL 3,149,500

CONTROL MECHANISM Original Filed Oct. 21, 1957 8 Sheets-Sheet 2INVENTORS JOHN H. Swxrs SIDNEY E. HAGERTY ATTORNEY Sept. 22, 1964 J. H.SWATS ETAL CONTROL MECHANISM Original Filed Oct. 21, 1957 8 Sheets-Sheet3 INVENTORS Joan H. SwATs SIDNEY E. HAGERTY BYfi /L .KI'TORNEY Sept. 22,1964 J. H. SWATS ETAL 3,149,500

CONTROL MECHANISM Original Filed Oct. 21, 1957 8 Sheets-Sheet 4INVENTORS Jon-m H. SwA-rs SmNEY E. HAGERTY ATTORNEY Sept. 22, 1964 J. H.swATs ETAL 3,149,500

CONTROL MECHANISM Original Filed Oct. 21, 1957 8 Sheets-Sheet 5INVENTORS JOHN H. SWATS SIDNEY E. HAGERTY BYW a AT TOR NEY P 22, 1964 J.H. SWATS ETAL 3,149,500

CONTROL MECHANISM INVENTORS .J" Jorm H. Swxrs SIDNEY E. HAGERTY BYW %WATTORNEY Sept. 22, 1964 J. H. SWATS ETAL 8 Sheets-Sheet 'T IIZ INVENTOR3JOHN H. SWATS SIDNEY E. HAGERTY wwv ATTORNEY Sept. 22, 1964 J. H. swATsETAL 3,149,500

CONTROL MECHANISM Original Filed 001:. 21, 1957 8 Sheets-Sheet 8 EELEASEL000 LBJ.

INVENTORS JOHN H. dwqTo BY SIDNEY E. HAGEETY ATTORNEY United StatesPatent 3,149,500 CONTRGL MECHANISM .Iohn H. Swats and Sidney E. Hagerty,South Bend, Ind assignors to The Bendix Corporation, South Bend, Ind, acorporation of Delaware Continuation of application Ser. No. 691,399,Get. 21, 1957. This application Apr. 13, 196i, Ser. No. 192,754 16Claims. (El. 74S3I) This invention relates to a control mechanism andparticularly to the operating portion of a parking brake mechanism whichis actuated by foot-applied effort. This application is a continuationof US. application Serial No 691,390, filed October 21, 1957, nowabandoned.

It is usually the practice in vehicle brake systems to provide bothservice and auxiliary brake applying systerns, the latter being used forparking and also in the event of failure of the service brake applyingsystem. The auxiliary brake aplying system may be associated with abrake which is separate from the service brakes, or it may be associatedwith the service brakes. The present invention is adapted for botharrangements.

While most of the park ng brake systems are actuated by hand, it isgenerally recognized that greater input effort can be developed by usinga foot-operated actuating mechanism. The reason for this is that greaterinput effort can be developed by pressing downwardly on a pedal with thefoot than by a backward yank or drawing eiiort applied manually to anactuating lever.

With some of the foot actuated parking brake systems, there is requireda releasing effort which is proportional to the applying effort. Whileit is desirable that parking brake systems have an operating mechanismby which it is easy to develop a maximum amount of applying effort, itis obvious that this input eitort should not necessitate releasingforces which are impracticably high. If the release effort isproportional to the input efitort, it is quite possible that theoperator cannot develop enough force to release the brakes once they areapplied. This would be especially true if the releasing mechanism werehand-operated and the applying mechanism foot-operated.

Accordingly, it is an object of this invention to provide a parkingbrake mechanism in which the effort required to release the brake isconstant irrespective of the input effort, thereby enabling constructionof a satisfactory foot-operated, hand released parking brake operation.

Another object of the invention from a performance standpoint is thatthe parking brake operating lever can be moved to any position betweentwo established stops and locked in a preferred position so that anydesired applying effort can be maintained on the parking brake, thisapplying efiort being maintainable by a locking mechanism associatedwith the applying mechanism.

From a construction standpoint, it is an object of the invention toprovide a simple operating mechanism which is made from a minimum numberof parts, most of these parts being constructed by stamping operations.

It forms an important part of the present invention from a constructionstandpoint that there is provided a depending foot-operated lever, andan associated transverse drum, this drum being co-movable with theapplying lever. A locking mechanism, consisting of a circularly woundspring, is provided in conjunction with the drum and has a one-waygripping function with respect to the drum so that the drum is permittedto turn in one direction and may thereafter be locked in any selectedangular position by the spring member which prevents turning of the drumin an opposite direction. A further construction feature of theinvention is a release mechanism adapted to expand a portion of thespring, this expansion serving to release the gripping effect of thespring on the 3,149,509 Patented Sept. 22, 1954 ice drum, and thereafterpermit return of the drum and release of the parking brake. Thisexpansion of the spring can be acomplished either by manual, pedal, orother mechanical means.

By means of this simple arrangement of parts which are reduced in numberinsofar as possible, there results an economical but functionallysatisfactory applying mechanism.

Another object of this invention is to provide a novel means forsecuring one free end portion of the circular spring member to a fixedsupport.

It is a further object of this invention to provide a novel method ofmaking the parking brake applying mechanism.

Other objects and features of the invention will become apparent from aconsideration of the following description, which proceeds withreference to the accompanying drawings, wherein:

FIGURE 1 is an isometric view of a foot-operated park ing brake applyingmechanism, constituting one embodiment of the invention;

FIGURE 2 is another isometric view of the same embodiment;

FIGURE 3 is a side view of another embodiment of the invention, in whichboth the applying and releasing mechanisms are pedal-operated;

FIGURE 4 is a front view of the operating mechanism, looking in thedirection indicated by the arrows 4-4 in FIGURE 3;

FIGURE 5 is a side elevation of a further embodiment of the invention,in which the applying mechanism is pedal-operated and manually released;

FIGURE 6 is a top View of the applying mechanism shown in FIGURE 5,looking in the direction indicated by the arrows 66 in FIGURE 5;

FIGURE 7 is a side elevation of a further embodiment of the inventionshowing a different mounting and releasing arrangement for thepedal-operated parking brake, the release mechanism being manuallyoperated;

FIGURE 8 is a top view of the operating mechanism shown in FIGURE 7,looking in the direction indicated by arrows 88 in FIGURE 7;

FIGURE 9 is a side eleavtion of the final embodiment of the inventionshown without a mounting bracket;

FIGURE 10 is a sectional view of a final embodiment of the inventiontaken on line 1t91i3 of FIGURE 9;

FIGURE 11 is a top view of the operating mechanism shown in FIGURE 10,looking in the direction indicated by the arrows 13l11 in FIGURE 10;

FIGURE 12 is a side elevation of the mounting bracket for the operatingmechanism shown in FIGURES 9-11;

FIGURE 13 is an end view of the mounting bracket shown in FIGURE 12,looking in the direction indicated by the arrows 13-13 in FIGURE 12;

FIGURE 14 is a sectional view, taken on the line 1414 of FIGURE 12,showing the tabs formed for securing one free end of the brake spring tothe bracket;

FIGURE 15 is a side elevation of the complete assembly of the operatingmechanism and mounting bracket shown separately in the previous figures;

FIGURE 16 is a sectional view, taken on line 1616 or" FIGURE 15, showingthe method of securing one free end of the brake spring to the mountingbrackets;

FIGURE 17 is a graph showing actual experimental data of the brakerelease characteristics of the invention.

Referring now to FIGURES 1 and 2, the applying mechanism, designatedgenerally by reference numeral Iii, comprises a depending lever or pedal12 having a pad 14 at one remote end thereof against which the operatorapplies his foot to actuate the parking brake. A cylindrical drum it: iswelded or otherwise secured to an enlarged end 1.8 of the pedal 12. Thecylindrical drum 16 9.2 is flanged at 2% and welded around its peripheryto the enlarged end 18 so as to be securely connected thereto. Thus,when the pedal 12 is caused to pivot, the drum 16 will turn therewith.The drum 16 and pedal 12 pivot on a stud 22 which is passed through boththe pedal and the center of the drum. The end 24 of the stud 22 isreduced in diameter and threaded to assist in mounting the entirestructure of the applying mechanism.

A mounting bracket 26 has spaced apart sides 28 and 3% which, inconjunction with the joining side 32, form a U-shaped construction. Theside 30 extends on the opposite side of the drum to form additionalsupport for the stud 22. The stud 22 is thus journalled at its ends onsides 28 and 30 of the mounting bracket. An opening 34 is also providedin side 28 and a fastener passed through the opening 34. The threadedend 24 of the stud 22 and the fastener (not shown) received through theopening 34 are received in a side wall (not shown), which forms part ofthe interior compartment of the vehicle.

The enlarged end 18 of the pedal 12 (FIGURE 2) has an integrally formedprojecting lug 36 which is apertured at 38 for connection with anapplying cable which leads to the brakes.

A portion 40 (FIGURE 1) of the side 30 is struck from the side 30 andbent transversely to form a seat for a rubber stop 42 which is designedto limit rotation of the lever 12 in a brake release direction. Aprojecting nib (not shown) is formed integrally with the enlargedportion 18 of the lever 12; this nib moves into contact with the stop 42to prevent further rotation of the lever 12.

Surrounding the outer periphery of the drum 16 is a circularcross-section coil spring or other coiled flexible member 44 whose innerdiameter is less than the outer diameter of the cylindrical portion ofthe drum 16, thus providing an interference fit between the two parts.The spring 44 consists of a number of coils which are arranged closelytogether with respect to each other and which are expanded over thedrum. In so doing, the springs exerts a resilient gripping force on thecylindrical surface of the drum. The one end 46 of the spring .iswrapped around an anchor bolt 48 which is received in side 2%, the end46 being thus fixed and nonmovable with respect to the drum 16.

Thus, when effort is applied to the pedal 12, the spring 44 will uncoiland allow the drum to be turned in that direction. When the tension inthe applying cable connected at 38 attempts to turn the pedal 12 anddrum 16 in the opposite direction, the spring 44 will coil tighter,increasing its frictional grip on the drum and prohibit the drum fromturning in that direction.

A ridge 50 is drawn in the side 28. This ridge is generally circular andhas a depressed circular recess 51 in its center that surrounds thatportion of the spring end 46 which is bent around the anchor 48. Thisridge and recess serve to hold the spring end 46 with respect to theside 28. The ridge 59 is not formed completely around the anchor 48thereby allowing a portion of the spring to lie flat against the side28. The end 46 of the spring 44 which is hooked over the anchor 48 isheld against the side 28 by means of an enlarged end 52 of the bolt 48and a washer.

The coil springg 44 terminates at the other end in a straight portion 54which projects tangentially from the drum 16 and has an eyelet 56 formedin the end thereof. A manually operated lever mechanism (not shown) isarranged to exert effort on the straightened end 54 to bend itdownwardly, thus expanding the adjacent coils of the spring andrelieving a part of the frictional gripping force between the coils andthe drum 16 to permit the cable, which is secured to opening 38, toswing the pedal 12 in a brake releasing direction. The return of thepedal 12 is limited by re-engagement of the integral nib with the stop42. The release mechanism utilized to expand the coils of the spring maybe constructed so as to maintain constant expansion of the spring whichpermits the brake to be released after actuation merely by the operatorremoving his foot from the pedal 12. Thus, the described applyingmechanism can be adapted to allow the drum to be turned in eitherdirection.

As described, the bracket can be mounted on the side wall of the driverscompartment, the pad 14 of the pedal 12 normally being contacted by theleft foot of the vehicle operator. The pedal and applying mechanism aresuspended sufliciently to the side and sutficiently high so as not tointerfere with the other vehicle operating members. The mounting portionof the bracket consists of the threaded end 24 of the pivot stud 22, thefastener member received through opening 34, and the threaded end ofanchor 48. This three-bolt mounting for the bracket is sufiicient tohold the operating mechanism against any of the shear stress developedduring brake application.

Referring next to the embodiment 10a shown in FIG- URES 3 and 4, partscorresponding to those previously described will receive the samereference numeral, but include further the subscript a to distinguishthe part from the previous embodiment.

A pedal 12a having a foot pad 14a is mounted for pivotal movement on apivot bolt 22a which is supported at opposite ends on a fixed bracket26a. The output end 36a of the applying lever has fastened thereto abrake applying cable 57 passing through a conduit 58 which is secured tothe fire-Wall 68 of the vehicle. The cable 57 leads to the parking brakemechanism and a pulling effort exerted by the output end 36a on thecable 57 is ultimately transmitted as actuating effort on the brake.

Referring to FIGURE 4, a drum 16a having a flanged portion 2% is weldedor otherwise secured in some suitable manner around its periphery to theportion 18a of the pedal 12a. Thus, when the pedal 12a is caused topivot the drum 16a is caused to turn therewith.

The position of the applying mechanism in FIGURE 3 is a normallyreleased position. The portion 36a of the applying lever is inengagement with stop 42a, the stop 42a being secured to part of themounting bracket 26a.

To lock the applying pedal in its various angular positions, there isprovided a coil spring or other coiled flexible member designatedgenerally by reference numeral 44a. The one end 46a is turned back andreceived through an opening in a transverseportion 62 of the bracketwhich joins the spaced apart sides 28a and 36a of the bracket.

A number of coils of the spring are formed about the outer cylindricalsurface of the drum 16a just as in the previous embodiment. The innerdiameter of the spring is less than the outer diameter of the drum 16::so that as the coils are forcibly expanded or sprung over the drum 16athey will exert a gripping action on the drum 16a. The coil springterminates at the other end in a straight, transverse portion 54a whichis secured to a floating link 64. The link 64 is joined through a pivotpin 66 to release lever 68. The release lever 68 is fulcrumed at 70 tothe applying pedal 12a. At the end of the release pedal 68 is a pad 72which is pushed on by the toe of the operator to release the lockingportion of the applying apparatus and permit brake release.

In operation, the operator pushes with his foot on pad 14a swinging thepedal 12:: about its pivot and turning therewith the drum 16a. Theturning of the lever about its pivot point develops a pulling force onthe cable 57 to apply the brake. Thus, the degree of brake applyingforce is determined by the amount of turning of the lever and drum 16a.When the applying effort on the pad 14a is relieved, turning of thepedal 12a in a brake release direction is prevented by the grippingaction of the spring 44a, which serves as a one-way brake preventingbrake relase. It thus happens that the applying apparatus is locked in abrake applying position, and this position can vary to any extentdesired to give any degree of braking effort. With the applyingapparatus thus held in a locked position, the brakes are applied and thevehicle is retarded against motion or, in the case of an emergency brakeapplication, the brakes develop a retarding eflort tending to slow thevehicle wheels and stop their rotation.

To release the applying mechanism, the operator needs only to push onthe pad 72, thereby pivoting the release lever 68 on the fulcrum 70, andcausing the floating link 64 to push outwardly on the end 54a of thespring which expands adjacent the coils of the spring and releases thefrictional gripping force of the coils on the drum 16a. When the brakespring 440 does release its force on the drum 16a, the tension force onthe applying cable 57 will swing the applying lever 12a until 36a isagain brought into engagement with the stop 42a thereby relievingapplying force on the brakes.

Referring next to the embodiment shown in FIGURES 5 and 6, partscorresponding to those previously de scribed will receive the samereference numerals, but include the subscript b.

There is included in this embodiment 1% an applying pedal 12!) which ispivoted at 22b and has a portion 36b adapted for connection with anapplying cable (not shown). A drum 16b having a cylindrical surface issecured to the pedal 12b and is turnable therewith when effort isapplied to the pedal 12b to actuate the brake. A one-way brakeconsisting of a coil spring 4412 is used to lock the pedal 12!) in anydesired angular position, this angular position determining the amountof brake applying force communicated to the brake. When it is desired torelease the brake, the operator merely pulls on handle 74, which islocated on the dash 75. A rod 76 connects the handle 74 and the free end541) of the spring 44b. The end 5% is thus pulled away from the drum,expanding the adjacent coils of the brake spring and relaxing thefrictional grip of the spring 4417 on the drum lob. This permits thepedal 12b to be returned to its original position wherein a portion ofthe pedal 12b contacts a fixed stop, just as in previous embodiments.The applying mechanism 1% is mounted on the firewall 77, as shown.

In this embodiment the brake is pedal-operated and locked and thereaftermanually released by pulling on the handle 74.

Referring next to the embodiment 100 shown in FIG- URES 7 and 8, whereinthe reference numerals will include the subscript c to distinguish themfrom parts previously described, there will be shown a method in whichmanual release occurs by pushing down on a manually operated lever.

The pedal 120 is fulcrumed at a portion between its ends on pivot pin22c. Applying effort is exerted against the pad 140 to swing the pedaldownwardly, and develop pulling force on the applying cable which leadsto the brake. A one-Way brake spring 44c grips cylindrical drum 160which is fixed to the pedal the same as in the previous embodiments.When it is desired to release the brake. the handle 74c is pusheddownwardly as indicated by the dotted arrow in FIGURE 7. The free end54c of the spring is pushed downwardly thereby expanding the adjacentcoils of the clutch spring 44c. When the coil spring is thus expanded,its frictional grip on the drum 160 is relaxed sufficiently to permitthe applying cable to return the pedal 120 to its original positionwherein it contacts a fixed stop just as in the previous embodiments.

There is some advantage to this release technique since the handle 74cinstead of being drawn outwardly can merely be swung downward.Considerable force can be developed in this manner. Mounting bracket,designated generally by reference numeral 260, has a number of holesindicated at 78 which can receive fasteners (not shown) to connect thebracket 26c with a portion of the vehicle in the interior compartment onthe firewall or side kick panel, etc.

Referring next to the embodiment 10d shown in FIG- URES 9, l0 and ll,portions of the actuating system corresponding to those previouslydescribed will be referred to with the same reference numeral butinclude also the subscript d to distinguish them from previouscomponents.

In FIGURES 9, 10 and 11, there are shown detail views of the applyinglever components without the mounting bracket. The parking brakemechanism is made up of two stampings 8t and 82. The stamping is formedinitially as a flat member and has at the one end a bent-over pedal half84 and a transverse strengthening rib portion 86. Centrally of thestamping is a drawn cylindrical portion 83 having an opening 9%. Thedrawn portion 33 has a cylindrical drum section 92 which is combinedwith the spring clutch member 94. A portion 96 of the drawn section 88lies flat against stamping 82 and is welded at 93 to the stamped portion82 so that the two portions together make up the pedal and drumassembly. The stamping 82 has a transverse pedal portion 109 which is inalignment with pedal portion 84 of the stamping 86 to make up thecomplete pedal pad 14d. Likewise, a strengthening web M32 is formedsymmetrically with portion 36 to provide additional transversestrengthening.

At the opposite end 1154 of the pedal 14d, the two stamping portions lieflatly together and an opening 106 is provided therein for attachmentwith an applying cable. The spring 94 in contrast with the previouslydescribed springs, is rectangular in cross section and lies flatlyagainst the drum surface to provide maximum gripping surface along theentire lateral width of the drum. Because of the added gripping surfaceof the flat wire, a narrower drum surface is required to provide lockingaction on the pedal.

FIGURES 12 and 13 are front and side views, respectively, of themounting bracket. The mounting consists generally of a U-shaped bracketwhich serves to pivotally suspend the actuating pedal 12d. The bracketconsists of two spaced sides 198 and 11% which are joined by portion112. The bracket is fastened to the side kickboard in the driverscompartment by means of fasteners (not shown). These fasteners arereceived through opening 114 in the side 19%. Openings 115 in sides 19%and are to receive the stud upon which the pedal assembly pivots. Anopening 116 is provided in side 112 for the applying cable which isthreaded through the opening for attachment with opening 106 in theapplying pedal 12d. Side 11% has a tab 118 which is formed integrallytherewith, this tab being struck from the side 110 and bent over so asto provide a seat for a stop 132 which limits movement of the applyingpedal in a brake release direction.

The side 1198 is adapted for securement with the spring 94. Referring toFIGURES 12, 14 and 15 at the upper edge 12% of the side 1% there is asheared portion which permits a tab 122 to be bent away from the side.Also in side 1&8 is a struck offset finger 124.

Referring next to FIGURES l0, l5 and 16, there will be described thefinal assembled brake pedal and bracket. In FIGURE 10, the spring 94 isstretched over drum section 92 of the stamping 3'!) and thereafter thestamping 82 is welded to the stamping S6 at 98 to hold the two stampingstogether. The two stampings thus enclose the spring 94. The two joinedstampings, along with the spring, are now ready for attachment with thebracket. Referring to FIGURES l5 and 16, as the pedal is fitted betweenthe sides of the bracket, the looped end 126 of the spring is caused toslide between the tab 122 and the side 198, and the end of the loop 126passes between the finger 12-4 and the side 1%. Thereafter, the pedal isheld in place by means of a pivot pin 12% which passes through openings91) in sides 86 and 82 and the openings in sides 1% and 110 of themounting bracket.

The end 126 of the spring is held permanently in place by swaging thetab 122 back to its original shape. Referring to FIGURE 15, the portion13% of the tab is brought back into conformance with the side 1438 ofthe bracket and the portion 122 (FIGURE 16) lying ad- 7 jacent thespring ecomes enlarged and bulbs out to lock the end and hold it inplace. The finger 124 is then crimped tightly against the end 126 toprovide further locking action on the end of the spring.

To apply the brake, the pedal pad 14d which is made up of portions 84and tilt) is depressed (referring to FIG- URE 15), thus rotating theapplying lever clockwise on pivot 128. \Vhatever angular position thepedal 160 is moved to by the operators effort, the pedal will be held inlocked position after the applying effort is released by means of theclutch spring When it is desired to release the brakes, manual or pedaleffort can be used for pulling the end 134 of the spring away from thedrum 92. When the end 134 is pulled away, the coils of the spring areexpanded and this releases their gripping effort on the drum and permitsthe tension in the applying cable to rotate the pedal counterclockwise(FIGURE 15) until the pedal engages with a resilient stop 132 which isfitted into'tab 113.

A method of manufacturing the control mechanism is disclosed in ourco-pending application U.S. Serial Number 102,881, now US. Patent No.3,069,764.

'There is shown in FIGURE 17 an operational advantage of all of theembodiments described. This advantage can be stated in terms of therelease load vs. cable load. By cable load is mean the amount ofapplying force which is developed on the applying pedal and communicatedto the brakes as applying elfort thereon. The release load is a measureof the amount of effort that needs to be developed to release the brake.It is characteristic of the invention that with a given brake, pedal andbrake-spring design, that the release load remains constant regardlessof the amount of applying effort which is applied to the brakes.Referring to FIGURE 17, which is a graph showing actual exepirmentalevidence of the brake release characteristics, it will be seen that therelease load does not vary appreciably regardless of the cable load.This means that, regardless of the applying effort which is exerted onthe brakes by the applying pedal in its locked position, there will beno change in the releasing eifort necessary to unlock the applying pedaland allow it to return to its original position thereby relieving thebrake applying load. We regard this as a substantial advantage in thatmost people are capable of developing considerably more force with theirfoot in applying the footoperated parking brake than they are inreleasing the brake by a manual pulling or pushing operation, and that,from past experience, it is quite possible for the vehicle driver toapply the brake with such force that it is impossible or very diflicultto release the brake with the releasing means provided.

The different lines which are shown in FIGURE 17 indicate six differentrelease loads which can be provided depending upon the gripping forcebetween the coil spring and the drum, this being obtained by selectingthe relative diametral dimension of the spring and drum, respectively.Where the inner diameter of the spring coil is very much smaller thanthe drum, then the gripping action of the spring is greater and developshigher orders of releasing loads, but these loads do remain constantirrespective of the applying force which determined the angular positionof the pedal in its locked position. Likewise, although the differentrelease load is possible as indicated with the other five, this releaseload does remain constant.

Although there are only a few selected example embodiments of theinvention which have been chosen to describe the invention and itsmethod of manufacture, it will be appreciated that these are merelyillustrative of the invention and are not to be interpreted asrestrictive thereof.

It is intended that such revisions and variations of the invention asare reasonably expected on the part of those skilled in the art will beincluded within the scope of the following claims.

We claim: e

l. A parking brake mechanism for vehicles comprising a support memberfor securing said mechanism to a fixed part of a vehicle, a stop mountedon said support member, a mechanically operated applying lever having aportion intermediate the endsthereoffulcrumd upon said support, saidleverhaving a portion thereof so disposed to engage said stop when saidlever is in an initial position, a drum secured to said applying leverand pivotally mounted between portions of said support member, a coiledflexible member wrapped tightly around the periphery of said drum andgripping the same, one end of said coiled member being secured to thesupport member, a second lever member pivotally mounted on the applyinglever, and an articulated link connected to one end of said secondlever, the other end of said link being secured to the'other free endportion of the coiled member so as to release the grip of said coiledmember on said drum upon actuation of the second lever member.

2. A parking brake mechanism for vehicles comprising a supportingmember, an applying lever having a portion intermediate the ends thereoffulcrumed upon said supporting member, a drum connected to said leverand turnable therewith, a coiled flexible member wrapped around theperiphery of said drum and gripping the same, one end of said flexiblemember being secured to the supporting member, and manually operatedmeans operatively secured to the other end of said coiled flexiblemember for releasing the grip of said coiled member on said drum.

3. In combination with a brake, an applyingmechanism comprising asupporting member, an applying lever having a portion intermediate theends thereof fulcrumed upon said supporting member and having one endthereof operatively connected to the brake, a drum turnable with saidlever, a-coiled flexible member wrapped around the periphery of the drumand gripping the same, said coiled member having one free end portionconnected .to the supporting member, and releasing means connected tothe other free end portion of said coiled flexible member, saidreleasing means being constructed and arranged to expand the coils ofthe flexible member to relieve their frictional grip on the drum uponactuation of said means and thereby release the brake.

'4. In combination with an applying mechanism in accordance with claim3, said releasing means comprising a manually operated handleoperatively connected to said other free end portion ofthe coiledflexible member to allow the coils thereof to relieve their frictionalgrip on the drum when said handle is forced downwardly, therebyreleasing the brake.

5. An applying mechanism according to claim 3 in which the releasingmeans comprises a manually operated handle operatively connected to saidother free end portion of the coiled flexible member to allow the coilsthereof to relieve their frictional grip on the drum when said handle ispulled outwardly thereby releasing the brake.

6. An applying mechanism according to claim 3 in which the connectionbetween said one free end portion of the coiled flexible member and thesupporting member comprises a circular ridge formed on the supportingmember, a circular recess formed in the center of said ridge, an openingin the center of said recess, and an anchor received in said opening,said one free end portion of the coiled flexible member being wrappedaround said anchor and fit into the circular recess to secure said onefree end portion to the supporting member.

7. In combination with a brake, a brake applying mechanism comprising asupport, a lever fulcrumed upon said support and having a portionthereof operatively connected to the brake, a drum turnable with saidlever, a coiled flexible member wrapped around the periphery of saiddrum and having one free end portion connected to the support, andreleasing means connected to the other free end portion of said coiledflexible member, said means being constructed and arranged to expand theflexible coiled member causing the member to unwrap from the drumwhereby the force required to cause said release is the same regardlessof the position of the loci;- ing force exerted by the coiled member onsaid drum.

8. A control mechanism comprising a supporting member, a lever pivotallymounted thereon and having an output end and an input end, a drumturnable with said lever, a coiled flexible member Wrapped around theperiphery of said drum gripping the same and having one end secured tothe supporting member so as to allow turning of the drum in onedirection only and thereby providing an unlimited number of lockingpositions for said lever between a fully applied and fully releasedposition, and means to release said coiled flexible member from its gripon the drum to permit turning of the drum and lever.

9. A control mechanism comprising a lever fulcrumed at a pointintermediate the ends thereof, a drum turnable with said lever, a coiledflexible member wrapped around the outer periphery of said drum topermit turning of the drum in one direction only, means for unwrappingsaid flexible member to permit turning of said drum with respect to saidflexible member in the direction opposite to said one direction, andmeans for mounting said applying mechanism to a fixed support.

10. The control mechanism of claim 9 in which the coiled flexible memberis of rectangular cross section the least width dimension of whichextends laterally across the drum.

11. The control mechanism of claim 9 in which the coiled flexible memberis of a square cross section.

12. A control mechanism comprising a cylindrical member, a coiledflexible member wrapped around the outer surface of said cylindricalmember and exerting by virtue of the construction a frictional forcethereon, releasing means for relieving the frictional force exerted bysaid coiled flexible member on said cylindrical member, and means toprevent said coiled flexible member from turning with respect to saidcylindrical member, whereby said cylindrical member is prevented fromturning in one direction by said frictional force and turnable in eitherdirection upon relief of said frictional force by said releasing means.

13. A brake applying apparatus comprising a brake pedal, means forlocking said brake pedal in the desired angular setting which determinesthe brake applying effort developed through said pedal, said meansincluding a cylindrically shaped drum operatively secured to said pedaland movable therewith, and a coil spring expanded over said drum to bein gripping engagement therewith, one end of said spring being heldfixed so that turning of said drum and pedal is prevented in onedirection by the wrapping action of said spring, the other end of saidspring being floatable to permit turning of the drum and pedal in theother direction to allow brake application, and release meansoperatively connected to the other end of said spring to expand thespring and relieve the gripping of said spring thereby permittingturning of said drum in said one direction, to release the pedal fromits locked position and therefore release the brake.

14. A brake applying apparatus according to claim 13 in which said pedalis formed of two pedal halves located side by side and connectedtogether, and said drum portion is formed integrally with one of saidpedal halves and is located therebetween.

15. The brake applying apparatus of claim 14 including a pivot pinreceived through openings in the spaced apart sides of said pedal halvesand journalled therein, and a mounting bracket having sides extending oneach side of said pedal to receive opposite ends of said pin topivotally support said applying apparatus.

16. A control mechanism comprising a support member, a stop mounted onsaid support member, an applying member having a portion intermediatethe ends thereof fulcrumed upon said support, said applying memberhaving a portion thereof so disposed to engage said stop when saidapplying member is in an initial position, a drum secured to saidapplying member for movement therewith and rotatably mounted to saidsupport member, a coiled flexible member wrapped around the periphery ofthe drum and gripping the same, said coiled member having one free endportion connected to said support member, and releasing means connectedto the other free end portion of said coiled flexible member, saidreleasing means being constructed and arranged to expand the coils ofthe flexible member to relieve their grip on the drum upon actuation ofsaid releasing means.

References Cited in the file of this patent UNITED STATES PATENTS Re.16,565 Myers Mar. 1, 1927 787,788 Pinard Apr. 18, 1905 823,971 RemondyJune 19, 1906 2,629,288 Jenssen et al. Feb. 24, 1953 2,881,881 Sacchiriet al. Apr. 14, 19 59

1. A PARKING BRAKE MECHANISM FOR VEHICLES COMPRISING A SUPPORT MEMBERFOR SECURING SAID MECHANISM TO A FIXED PART OF A VEHICLE, A STOP MOUNTEDON SAID SUPPORT MEMBER, A MECHANICALLY OPERATED APPLYING LEVER HAVING APORTION INTERMEDIATE THE ENDS THEREOF FULCRUMD UPON SAID SUPPORT, SAIDLEVER HAVING A PORTION THEREOF SO DISPOSED TO ENGAGE SAID STOP WHEN SAIDLEVER IS IN AN INITIAL POSITION, A DRUM SECURED TO SAID APPLYING LEVERAND PIVOTALLY MOUNTED BETWEEN PORTIONS OF SAID SUPPORT MEMBER, A COILEDFLEXIBLE MEMBER WRAPPED TIGHTLY AROUND THE PERIPHERY OF SAID DRUM ANDGRIPPING THE SAME, ONE END OF SAID COILED MEMBER BEING SECURED TO THESUPPORT MEMBER, A SECOND LEVER MEMBER PIVOTALLY MOUNTED ON THE APPLYINGLEVER, AND AN ARTICUALTED LINK CONNECTED TO ONE END OF SAID SECONDLEVER, THE OTHER END OF SAID LINK BEING SECURED TO THE OTHER FREE ENDPORTION OF THE COILED MEMBER SO AS TO RELEASE THE GRIP